Joining the rear diff club

[Wlepse]

Oh crap! Was clearing the snow today and noticed what look like drops coming from the back of the wagon. When things clear up I will have to get under there to access the situation. But not at all happy. Especially since the abilities of this AWD don't seem to live up to what you'd expect from the design. My old Audi A4 had no traction or stability control and would just claw itself through snow banks. Today the TourX got stuck. Tried turning off the traction and stability control and still nothing. I know 90% of snow performance is tire related, but I almost never ran dedicated snows on the Audi and that thing would be able to get through plow curls. The TourX actually made me concerned something was wrong because it was like bucking as it tried to shift power front to rear.

 

[Rhetoric]

I've had a completely different experience from yours, but I run dedicated snow tires. Outside of beaching it in a foot of snow, or mechanical issues, the GKN Twinster outperforms any Quattro or "Fraud wheel drive" system Audi sells.

 

[Wlepse]

I am sure it is fine on a normal road but trying to pull through a foot deep of snow that was about 2' out from the bumper and it was an epic fail. I really don't like the way it feels as it tries to transfer power. It felt like neutral dropping with clunks and pops. Never had that with the Audi. There was one year it plowed through a snow curl that was just about up to the mirrors on all seasons. So call the system what you like, so far between GKN and Subaru I would take the Audi.

Back to the seal issues...are the people that are seeing this also the ones that tend to drive in crappy conditions? Just wondering if that jerkiness I felt contributes to seal failures.

 

[bollox74]

I've not yet experienced any differential troubles and I'm in Winter #3 in Minnesota.

No problems with the AWD either with regular heavy MN snow and ice.

 

[adam728]

I am sure it is fine on a normal road but trying to pull through a foot deep of snow that was about 2' out from the bumper and it was an epic fail. I really don't like the way it feels as it tries to transfer power. It felt like neutral dropping with clunks and pops. Never had that with the Audi. There was one year it plowed through a snow curl that was just about up to the mirrors on all seasons. So call the system what you like, so far between GKN and Subaru I would take the Audi.

Back to the seal issues...are the people that are seeing this also the ones that tend to drive in crappy conditions? Just wondering if that jerkiness I felt contributes to seal failures.

A huge variable is the type of snow as well. I used to do a lot of off roading in multiple different vehicles. I've driven around without issue is 36-40 inches of snow on the level, with drifts >4 ft. Lake effect fluff with no base, you could probably drop a sheet of notebook paper and it'd hit the ground. Same truck on the same tires had also been stuck on the lake in about 5 inches of very dense and melting snow. Tire slips, makes a little trough, and is sitting on a polished ice base. It would be like doing the AWD roller test, with all 4 tires on rollers.

All that said, no clunks or pops with the AWD here yet. I am slightly disappointed in the feel of the AWD though. Slightly. Rolling on the throttle and cornering on snow it seems like it stays FWD and understeers a fair amount before the rear comes into play. Depending on how easily I'm tickling the edge of traction it feels as though it could stay "fwd" forever. If more aggressive with the throttle it seems more seamless, with the rear coming into play immediately. My "dumber" AWD GMC Terrain is much more seamless in it's application and never seems to spin fronts without the rear being right in sync with them, but only had brake-application for transferring power.

I'm used to dumb trucks and Jeeps with a part time transfer case and many with lockers (or the terrifying spooled truck in snow). No guessing how it's going to respond from one time to the next.

 

[FavaBean]

It felt like neutral dropping with clunks and pops.

Yikes. I heard a few unexplained clunks and pops today when I was tooling around in the snow. I have yet to confirm the status of my seals.

We got only around 5 inches of wet snow. Generally, I was happy with the grip of my OEM tires with 45k on the clock with significant wear.

 

[ZB Commodore Owner]

When I had my RSV Commodore serviced last time the dealer told me there was an oil leak from the rear diff. The car had done about 28,000 km ( 17,000 miles). The leak cannot have been too bad as there were no drops on the garage floor.

They told me the problem was the breather which for some reason had become blocked. It sounded like it was a known problem.

When the diff heats up, pressure builds up inside the diff causing oil to be forced past the seal. Apparently the seal isn't usually damaged.

They asked me to take it back at around 30,000 km for a follow up check to ensure it's OK. I'm yet to do that.

 

[Wlepse]

Yikes. I heard a few unexplained clunks and pops today when I was tooling around in the snow. I have yet to confirm the status of my seals.

We got only around 5 inches of wet snow. Generally, I was happy with the grip of my OEM tires with 45k on the clock with significant wear.

I had not ever felt this before in normal driving in snow, even when I tried to play in a parking lot last winter. So you felt this in normal driving? I guess I feel a little better knowing someone else has experienced it. But I do agree this car tends to push a lot. My Subaru LGT did the same until I upgraded the rear sway, then it was much more playful in the snow.

When I had my RSV Commodore serviced last time the dealer told me there was an oil leak from the rear diff. The car had done about 28,000 km ( 17,000 miles). The leak cannot have been too bad as there were no drops on the garage floor.

They told me the problem was the breather which for some reason had become blocked. It sounded like it was a known problem.

When the diff heats up, pressure builds up inside the diff causing oil to be forced past the seal. Apparently the seal isn't usually damaged.

They asked me to take it back at around 30,000 km for a follow up check to ensure it's OK. I'm yet to do that.

Seems reasonable, some seals can tolerate some blow by without damage. But I would make sure you have the records to show you had the issue early on in case it continues to be an issue for you.

 

[Rhetoric]

I am sure it is fine on a normal road but trying to pull through a foot deep of snow that was about 2' out from the bumper and it was an epic fail. I really don't like the way it feels as it tries to transfer power. It felt like neutral dropping with clunks and pops. Never had that with the Audi. There was one year it plowed through a snow curl that was just about up to the mirrors on all seasons. So call the system what you like, so far between GKN and Subaru I would take the Audi.

Back to the seal issues...are the people that are seeing this also the ones that tend to drive in crappy conditions? Just wondering if that jerkiness I felt contributes to seal failures.

That just sounds like you have highly unreasonable expectations of what this system can do with all-seasons. Get a 4x4 truck if you want to plow snow on non "normal roads". We all have different preferences, but I would never expect this car to go through a foot of snow with ease. It also doesn't surprise me that this system has more "feedback" than the very simple AWD (and Fraud Wheel Drive) systems in Audis and Subis.

I could push snow over the hood of my TDI with EGTs at 8000 deg F until it melted into a lump if I wanted. I usually found a less snow covered path, though.

 

[FavaBean]

@Wlepse I think back now and a couple weeks ago, during normal driving it kind of felt like I hit the gas, then a moment later something popped. It sounded like a branch was chipped up below the car and hit the undercarriage.

I will now pay closer attention as to what I was doing leading up to the noise...but it makes reasonable sense that it may be the differential.

 

[MelsRegal]

In traditional rear wheel drive limited slip differentials, a popping or chattering sensation during turns indicated as a first step to add a bottle of GM friction modifier to permit the clutch plates to slip smoothly during turns. I do not know if this would apply to this new type of differential or if the sound you are hearing is more prevalent in turns.

 

[Wlepse]

@Wlepse I think back now and a couple weeks ago, during normal driving it kind of felt like I hit the gas, then a moment later something popped. It sounded like a branch was chipped up below the car and hit the undercarriage.

I will now pay closer attention as to what I was doing leading up to the noise...but it makes reasonable sense that it may be the differential.

The old Audi had electronic differential locks which was a cheap way to try to limit wheel spin in each corner by applying brake pressure to that wheel. Maybe this car does that too but more aggressively and that clamping of the caliper is what I was hearing? But I would have thought with traction and stability control shutoff this wouldn't be active.

 

[jdoodle]

Just picked my TourX up today. Took it in on Jan 21 after second seal replacement failed. Official diagnosis is: "fluid leaking from between axle seal and housing and at pipe fitting. Verify concern. Add dye to rear diff. road test and identify point of leak... yadaa, yadaa, yadaa...replace rear differential assembly." I confirmed with service advisor that rear diff is included in power train warranty. It sure is nice to have it back and get out of Malibu service loaner. They charged me $11.43 for "environmental" whatever the f*** that is. Now whether I keep it or not will just have to see but in the mean time will keep my eyes open for a 2015 or so Mercedes E63 AMG wagon at twice the price of the TourX but with 500 hp. 😈

 

[94cruiser]

What would you say if you saw this hack job after a diff. seal replacement?

Is this JB Weld? Is it hiding a larger dent, puncture, or hole?


Found a small spot of gear oil in one spot on the black part. Enough to dirty up two fingers. Believe it was not fully cleaned during the repair.

Another dealer confirmed that the driveshaft was damaged and it is indeed JB weld and that the vehicle needs to go back to the location this repair was performed to replace the damaged driveshaft.

 

[Wlepse]

What? That is freaking terrible. I would contact Buick and let them know that the work was not performed correctly and another dealer confirmed that. I had an issue with my wife's Ford that took several visits to the original shop and they still didn't fix it. Eventually Ford authorized us to go to another dealer and they would cover the repairs. But I had to show proof of the attempts and it was like pulling teeth to get them to do anything. But that is just aweful...and if I were Buick I would be pissed that they paid for such crappy work and they ended up with a pissed off customer.

 

[jdoodle]

Another dealer confirmed that the driveshaft was damaged and it is indeed JB weld and that the vehicle needs to go back to the location this repair was performed to replace the damaged driveshaft.

Wow, 94, that's incredible. Sounds like you've quite a fight ahead of you. Good luck with it.

 

[jdoodle]

After driving my TourX for a day it's developed a "rough" feeling to it. Hard to describe but it just doesn't feel smooth like it did before the diff. replacement. Best I can say is it feels like a subsonic vibration, the car isn't shaking but I can just "feel" it. Will take it back to the dealer to see what they say.

 

[BenD]

Hi folks, it’s been awhile since I wrote about this thread. Since I have a vibration issue and I’m fighting with GM to have that resolved, now I will have an interview with a mediator on February 24th. The mediator will decided if GM will be in obligation to pursue the diagnostic to found the issue or not. Car will be inspected if require by a third party expert. I’ll keep you informed. Meanwhile if you are Canadian, you can have access to a mediator to help you. It’s free and mediator decision’s irrevocable by the manufacturer.

CAMVAP - Home

www.camvap.ca

 

[Crispy]

We’re in the club with a seal replacement last November. 2018 X with 18k. I have not checked under our car yet since the fix but I did test this cars capability. We have a steep driveway with a hairpin turn in the middle and live in northern NY. I expected some sort of action, clunking, torque transfer or something on the hairpin in snow but it was pretty smooth. Last week we had a very slippery day with my ‘95 plow Wrangler struggling on marginal tires. I was actually stuck on a straight, steep section in the Jeep and had to back up. I brought the Tour X to the same spot for a test and it was impressive. Clawed right up from a stop with 2nd season snows on. I was impressed. We’ve owned five Audis on this driveway and everyone in everything has been stuck on it through the years.
Now I just have to get underneath and see if that seal is holding up 🥴.

 

[94cruiser]

Wow, 94, that's incredible. Sounds like you've quite a fight ahead of you. Good luck with it.

If you scroll up the thread you will see photos I posted.